The present invention relates to sportsballs, and more particularly to a durable sportsball adapted for mass production, moreover the sportsball can retain its spherical shape and distribute the impacting stress throughout the ball.
Sportsball such as soccer ball and volleyball, as shown in FIGS. 1 and 2, generally comprises a ball cover 11 and a bladder 12 disposed within the ball cover 11. The ball cover 11 is made of leather or synthetic leather such as polyurethane (PU) or polyvinyl chloride (PVC). As shown in FIG. 2, the synthetic leather is composed of an outer coating layer 111, an intermediate foaming layer 112 and an inner lining layer 113 to strengthen and support the foaming layer 112. The bladder 12 is a spherical rubber ball having a valve stem 121 affixed thereon.
The leather or synthetic leather is cut into a plurality of panels 110 with predetermined shape. For soccer ball, the most common shape of the panel 110 is pentagon and hexagon. In other words, the ball cover 11 of a soccer ball is made of 12 pieces of pentagonal panels and 20 pieces of hexagonal panels by hand sewing edge to edge. The spherical ball cover 11 of a volleyball consists of 18 pieces of rectangular panels hand sewn edge to edge. The inflatable bladder 12 is placed inside the ball cover 11 and its valve stem 121 is extended outside the ball cover 11 for air inflation. When air is pumped into the bladder 12 through the valve stem 121, the air inflates the bladder 12 to prop up the ball cover 11 and retain its roundness. Therefore, an inflated sportsball has a bouncing feature. The more air is inflated into the bladder 12, the sportsball has a better bounce.
The rigidity and durability of a conventional sportsball as described above merely depend on the structure of the ball cover 11 but not the soft rubber bladder 12. The structure of the ball cover 11 must be tough enough to absorb all the impact forces. Therefore, the panels 110, either made of leather or synthetic leather, must be further strengthened by affixing at least two more layers of coarse lining 114, 115 thereon in order to better support the ball cover 11 and resist the stress. The roundness and re-enforcement of the sportsball depend on the strength of the lining cloth. Hence, the material used for the lining cloth is very important that, it may increase the material cost of the conventional sportsballs. Basically, the additional linings 114, 115 are glued layer by layer on the inner lining layer 113 of the synthetic leather or the inner side of the leather before cutting into the panels 110, which increases a manufacturing adhesion step for the conventional sportsball.
However, the additional coarse linings not only increase the thickness of the ball cover 11, but also increase the hardness of the ball cover 11. Accordingly, the thick and hard panels 110 increase the difficulty of sewing the panels together by sewing machines, especially during sewing around the sharp corners of the panels 110, that is the weakest portion of the ball cover 10. It is the reason that why most of the formal or classic sportsballs are still hand made. The workers have to sew the panels 110 together one by one by hand. Normally, a skillful worker can only complete the sewing process of two sportsballs per a working day. It is extremely uneconomic and time consuming that would highly increase the manufacturing cost of the sportsballs.
Another serious shortcoming of the hand sewing sportsball is that it is nearly impossible to evenly sew the panels together under same tightness. Therefore, when the sportsball is inflated, the inflating bladder 12 would be propped by the bladder 12 to protrude outwardly at some less tightly constructed portions of the ball cover 11, so that the roundness of the sportsball is adversely affected. Moreover, the sewing threads may more easily be broken during heavy impact, so that thickened sewing threads should be used. In fact, no hand made sportsball is in absolutely spherical shape, that may affect the performance of the conventional sportsball. When the sportsball is hit on such protruded portion, it may not bounce to the desired direction. Besides, those weaker portions of the sportsball will more easily be worn out and those sewing threads at such portions may also more easily be broken.
Since the linings 114, 115 are made of cloth, they tend to stretch while the sportsball is hit. At that time, the sportsball would lose its spherical shape because of the lining stretching. Practically, the inflated bladder 12 is directly propped on the additional linings 114, 115, therefore the major stress supporting area of the sportsball is the connecting surface between the additional linings 114, 115 and the leather or synthetic leather of the ball cover 11. It is well known that the stress resisting ability and the durability of cloth material are poor. In other words, the additional linings 114, 115 are not strong enough to endure those inflating stress and impact stress, especially during the impacting of the sportsball. The additional linings 114, 115 will rip apart sooner or later that would cause the sportsball to be worn off and damaged.
Furthermore, the leather or the thickened and hardened synthetic leather ball cover 11 of the conventional soccer ball may make the soccer player feels hurt and pain during heading, especially to children and those training players. The volleyball which is constructed by such conventional ball cover 11 may also cause the volleyball player feels pain and uncomfortable during servicing, spiking and blocking. For children and training soccer players or volleyball players, such thickened and hardened ball cover 11 of the conventional sportsball would be too rigid and hard for them.
It is an object of the present invention to provide a sportsball which ball cover is well supported by a strengthened bladder. Therefore, no additional lining is required to adhered onto the ball cover that, it can lower the material cost and manufacturing cost of the sportsball.
It is still an object of the present invention to provide a sportsball which major stress supporting portion is the strengthened bladder.
It is still an object of the present invention to provide a sportsball which bladder has a better flexibility and impact resisting ability.
It is still an object of the present invention to provide a sportsball which is more durable and has a softer ball cover to reduce the painful during heading, especially suitable for children and training players.
It is yet an object of the present invention to provide a sportsball which has a better roundness even when it is over-inflated for 15 to 20% more than the standard pressure.
It is yet an object of the present invention to provide a sportsball made of leather, in which since the stress supporting and impact resisting portion is the strengthened bladder, but not the ball cover, the expensive leather panels of the ball cover can be made thinner to lessen the cost, and that an additional soft sponge pad layer can be adhered on an inner surface of the leather panel to soften and reinforce the leather ball cover.
Accordingly, a sportsball of the present invention includes a ball cover and a bladder. The ball cover has a valve hole provided thereon and consists of a plurality of panels connected edge to edge by machine sewing to form a roundness shape. Each of the panels has a predetermined shape and is made of synthetic leather, wherein the synthetic leather has an outer coating layer, an inner lining layer, and an intermediate layer which is integrally formed between the outer coating layer and the inner lining layer and is strengthened and supported by the inner lining layer. The bladder which is disposed inside the ball cover includes a rubber made bladder ball, an exterior web layer integrally provided on an entire outer surface of the bladder ball, and a valve stem which is mounted on the bladder ball and is extended through the valve hole of the ball cover to connected thereto for air inflation. The web layer includes at least an elongated strengthened thread evenly wound around and around the outer surface of the bladder ball. Therefore, the strengthened thread is overlapped to form the web layer to entirely embrace the bladder ball for supporting the bladder ball and resisting the stress and impact force of the sportsball.
The panels of the ball cover can also be made of thin leather with a pad layer adhered underneath for providing the softness and thickness of the ball cover.